Heads-up display with improved contrast

ABSTRACT

A heads-up display for a vehicle is in contrast to the windshield behind the display or the environment outside of the vehicle windshield. In this way, the heads-up display is more visible than prior art heads-up displays. In one embodiment, the windshield is tinted to be in contrast with the color of the heads-up display, at least over a small area. In other embodiments, the image forward of the vehicle is captured and sent to a control for the heads-up display. The heads-up display is then modified to be in contrast with the environment approaching the vehicle. In another embodiment, the window is modified to have a back glow over a small area. The heads-up display is directed onto this small area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 09/090,071, filed Jun. 3, 1998, now U.S. Pat. No. ______, the disclosure of which is hereby incorporated in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to several methods for improving the contrast between a heads-up display on a vehicle windshield and a background.

2. Background Art

Heads-up displays are utilized in many vehicle display functions. Essentially, a heads-up display is directed onto the windshield of a vehicle. The heads-up display provides information to the vehicle operator, such as the speed of the vehicle or other information with regard to the operation of the vehicle.

In the prior art, heads-up displays have typically included display lights which direct the light onto the interior surface of the windshield. However, in high glare situations, a heads-up display may be sometimes less visible than would be desirable. In addition, the background of a heads-up display is typically the oncoming surroundings of a vehicle. In some situations, there may be an arrangement of environmental factors that have made some heads-up displays difficult to see.

SUMMARY OF THE INVENTION

It is an object of the present invention to improve the contrast and visibility of heads-up displays in vehicles.

In a disclosed embodiment of the present invention, heads-up displays are provided with arrangements to give the displays better contrast and improved visibility. In one basic arrangement, the vehicle window is provided with a tinting at least in the area of where a heads-up display (HUD) is directed. The HUD is chosen to be in a color which contrasts relative to the tint. In this way, the effects of the environment will be less likely to dilute the visibility of the HUD.

In other options, a system for providing an indication to a control of the surrounding environment is provided. In one example, a camera captures images in front of the vehicle to identify the oncoming surroundings. This image is studied for color and/or for structural features. Depending on what is oncoming, the control will select an appropriate HUD color and/or pattern.

As an example, if the vehicle is heading into a bright blue sky, and there is little in front of the vehicle other than the horizon and blue skies, the control may select a color for the HUD other than blue, such as red. If a large red truck is in front of the same vehicle, the control may select blue for the HUD instead of red.

If the environment approaching the vehicle has many small features, such as a gravel road, it may be desirable for the HUD to be displayed in elongated bars, rather than in dots. Alternatively, if the oncoming environment has many elongated features, such as fields of crops, forming the display in small dots may be preferable.

Although examples are listed, the options depending upon the environment are endless. The Applicant will not attempt to exhaust all of the contrasting options for this aspect of the present invention. However, many different options are obvious and available.

In a third basic arrangement for providing contrast, some surface treatment is performed on the glass behind the area where the display is directed. As an example, the glass can be roughened. This can occur at the inner surface or at a surface between two panes. Light is directed off the roughened area, and forms a backlighting or “glow” around a small area. It is on the small area where the HUD is directed. The surrounding area makes the HUD easily visible. The light is not visible except at this small area. A small amount of light can be directed within the plane of the window at the area, such as from a source in the pillar.

These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a first embodiment of the present invention;

FIG. 2A illustrates a second embodiment of the present invention in a first situation;

FIG. 2B illustrates the second embodiment of the present invention in a second situation;

FIG. 3A illustrates the second embodiment of the present invention in a third situation;

FIG. 3B illustrates the second embodiment of the present invention in a fourth situation;

FIG. 4 illustrates another embodiment of the present invention;

FIG. 5A illustrates a cross-section of a first way of achieving the arrangement shown in FIG. 4; and

FIG. 5B illustrates a cross-section of a second way of achieving the arrangement shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 illustrates a vehicle 20 having a windshield 22. Windshield 22 is provided with a tint portion 23 at least in the area where heads-up display (HUD) 24 is directed by a source 25. Source 25 is shown schematically in FIG. 1. Preferably, the tint covers the entire windshield. In the present invention, HUD 24 is selected to have a color which contrasts to the color of tint 23. More preferably, HUD 24 has a color that includes effectively none of the primary color components of tint 23. As an example, tint 23 may be mainly a green tint while HUD 24 is mainly red. In this way, HUD 24 is in stark contrast to its background and quite visible. This embodiment provides a very simple method of increasing the contrast and visibility of a heads-up display and removing any diluting effect from light passing into vehicle 20.

The environment outside of windshield 22, or in front of the windshield, is the background for HUD 24. This environment can be various colors, or textures, and also can have a good deal of glare. This may make HUD 24 somewhat difficult to see. It is for this reason that tinted area 23 can provide benefits in increasing the contrast. Tinted area 23 need only be over a small area on the bottom of windshield 22 where HUD 24 is directed, though full windshield treatments would be more uniform for the user.

Tint 23 and HUD 24 are preferably selected such that they do not have the same primary colors in them. Obviously, a color having a small quantity of a primary color found in one of tint 23 and HUD 24 may be included in greater quantities in the other without avoiding the broader aspects of the present invention. The contrast would still be achieved. Through proper application, a color seen through tint 23 can never match the color of HUD 24.

FIG. 2A illustrates a vehicle 26 having a HUD 28. HUD 28 is selected to be in contrast with environment 30 approaching vehicle 26. In this embodiment, a camera 32 “snaps” an image of the upcoming environment. Cameras which are able to provide a digital image which can be processed are becoming widely utilized, and relatively inexpensive. Such cameras are being discussed as being incorporated into vehicles for many other operational purposes such as increasing the safety of driving and avoiding obstacles. Camera 32 is incorporated into the display system and communicates with a control 33 for a heads-up display output 25. Control 33 analyzes the environment image taken by camera 32 and develops a signal to output 25 to create a heads-up display which is in contrast to the environment.

In one example, HUD 28 is selected to be a different color than the background of the approaching environment. Of course, the approaching environment will always include many different colors. However, as one example, if vehicle 26 is approaching a relatively flat area with very blue skies as shown in FIG. 2A, HUD 28 may be selected to be a color other than blue, such as red, for example.

FIG. 2B illustrates vehicle 26 with a large red truck 37 in front of the vehicle. Control 33 would then change HUD 28 to another color, such as blue, for example.

FIGS. 3A and 3B illustrate further options in changing a heads-up display as appropriate for an approaching environment. As shown in FIG. 3A, if camera 32 sees that the approaching environment consists of land with many details, such as a gravel road 34, HUD 36 may be selected to be in elongated bars. This would make HUD 36 more visible than if it were a series of dots.

Alternatively, as shown in FIG. 3B, if the vehicle is driving into an area full of elongated crops 42, it may be desirable to have HUD 44 formed of dots. This would make HUD 44 more visible than if it were elongated bars.

Control 33 is able to identify certain characteristics of the approaching environment and select from the options of may different display colors and patterns. Of course, the designer will be able to program dozens of different patterns and colors which would all be easily attainable. The Applicant will not attempt to list all of those options. Instead, the inventive feature of the present invention is considering the environment and tailoring the HUD to be appropriate for the approaching environment.

FIG. 4 illustrates another embodiment wherein a portion of windshield 46 is provided with surface roughening 47. A light source 48 is positioned adjacent roughened portion 47. Light is directed off of roughened portion 47 and the light passes out through windshield 46 at all areas other than roughened surface 47. However, at roughened portion 47, a back-glow 50 is created. Back-glow 50 is then utilized as a base for HUD 52. HUD 52 is thus in contrast and quite visible. The roughened surface may be on the surface of a single-pane windshield, or at the intersection plane of a dual-plane or dual process windshield. Alternatively, during manufacture of a single pane, localized effects can be performed at a mid-point, such that the final pane has the effect of the surface at a central layer. Other methods including fiber alignment with the windshield glass, or stress induced localized micro-cracking may be used. This embodiment thus provides a good contrast for a heads-up display.

FIG. 5A illustrates windshield 46 formed of two panes 60, 62. Roughened area 47 is between the two panes. Light from source 48 passes within the panes of windshield 46 and creates the glow as described above.

FIG. 5B illustrates a second embodiment 70 wherein a single panel 72 is provided with roughened area 73. Coating 74 seals over area 73. Back-glow 76 is created similarly as described above.

The present invention has been disclosed somewhat schematically. The appropriate structure for creating heads-up displays, for modifying heads-up displays, and for controlling heads-up displays in consideration of the environment, etc., are all within the skill of a person in this art. The inventive aspects of the present invention relate to providing a contrast, and in some embodiments, providing a contrast based upon the approaching environment.

While preferred embodiments of the present invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the present invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the present invention. 

1. A heads-up display system comprising: a source for directing a heads-up display onto a windshield of a vehicle; and an arrangement for increasing the contrast of the heads-up display on the windshield relative to the background of the heads-up display on the windshield, wherein the arrangement includes a tint provided on the windshield, at least in the area where the heads-up display is directed, with the colors of the heads-up display and the tint being in contrast to one another.
 2. The system of claim 1 wherein: the colors of the heads-up display and the tint are selected such that the heads-up display includes at least one primary color void from the color of the tint.
 3. The system of claim 2 wherein: the tint is provided in an area of the windshield where the heads-up display is directed and the remaining area of the windshield is void of the tint.
 4. A heads-up display system comprising: a source for directing a heads-up display onto a portion of a windshield of a vehicle; and an arrangement for increasing the contrast of the heads-up display on the windshield relative to the background of the heads-up display on the windshield, wherein the arrangement includes a roughened surface on the windshield portion, wherein the arrangement further includes a light source adjacent to the windshield portion for directing light onto the roughened surface of the windshield portion in order to provide a backglow for the heads-up display.
 5. The system of claim 4 wherein: the windshield is a single-pane windshield, wherein the roughened surface is provided on either interior or exterior surfaces of the windshield.
 6. The system of claim 4 wherein: the windshield is a dual-pane windshield, wherein the roughened surface is provided between the windshield panes.
 7. A method of providing a heads-up display, the method comprising: directing a heads-up display onto a windshield of a vehicle; and modifying at least one of the heads-up display and the windshield relative to one another to provide greater contrast between the heads-up display and an image beyond the windshield.
 8. The method of claim 7 wherein: modifying at least one of the heads-up display and the windshield includes providing a tint on the windshield and includes selecting a color of the heads-up display which contrasts with the color of the tint such that the contrast between the heads-up display and the image beyond the windshield is increased.
 9. The method of claim 8 wherein: selecting a color of the heads-up display includes selecting the color of the heads-up display such that the heads-up display includes at least one primary color which is not included in the color of the tint.
 10. The method of claim 7 wherein: modifying at least one of the heads-up display and the windshield includes roughening a surface of the windshield and directing light onto the roughened surface of the windshield in order to provide a backglow for the heads-up display such that the contrast between the heads-up display and the image beyond the windshield is increased.
 11. The method of claim 10 wherein: the windshield is a single-pane windshield, wherein the roughened surface is provided on either interior or exterior surfaces of the windshield.
 12. The method of claim 10 wherein: the windshield is a dual-pane windshield, wherein the roughened surface is provided between the windshield panes. 